Another great set. I wish I could get guerreronis to flower here in the UK, really not enough winter warmth and especially light.
There is a form, under the field number of RS658, from Chilpancingo-Iguala, Guerrrero, that does flower easily for me, even when reasonably young. The spines are a bit different, and it has been suggested that it is an intermediate between guerreronis and nunezii.
There is another under the Lau 1096 field number that comes from Mezcala, Guerrero, that some think is an intermediate between guerreronis and meyranii ssp michoacan. That also flowers quite easily.
Most of the reported locations are in this area, so it would seem that M. guerreronis is variable, not just in spination but also in flowering.